McAuliffe defended his actions Tuesday to reporters at an event in Alexandria. A law-enforcement official told The Associated Press on Monday that McAuliffe is the subject of a federal investigation looking at donations to his 2013 gubernatorial campaign.

McAuliffe said he believes the investigation centers around a donation connected to Chinese businessman Wang Wenliang. Federal law forbids foreigners from contributing to U.S. political campaigns, but McAuliffe said Wang has held a green card for nearly a decade and is a legitimate donor.

"We went back and checked, and our lawyers to the campaign said this man had been fully vetted, and clearly had the right," McAuliffe told reporters. "He owns a big company in the United States of America; he's a major donor to Harvard University. He's on the board of New York University."

McAuliffe said he didn't believe he'd ever met the donor in question but had met people from the man's company.

"It's concerning, and I'm sad for Virginia," said John Whitbeck, chairman of the Virginia Republican Party. "He's every body's governor, and Republican or Democrat alike we rely on our elected officials to conduct themselves with integrity."